Ventilation system

ABSTRACT

A ventilation system comprises ductwork, a fan for creating a current of air passing through the ductwork, and an air supply outlet for supplying outdoor air into a living space of a house by means of the current of air. The ventilation system further comprises an electrostatic atomizer located at the side of the air supply outlet. The electrostatic atomizer is configured to produce mist of charged fine water particles by means of electrostatic atomization to spray the mist into the living space.

TECHNICAL FIELD

The invention relates generally to ventilation systems and moreparticularly to a residential ventilation system.

BACKGROUND ART

Many houses have been tight and well insulated in recent years, andaccordingly ventilation systems are required to be installed in thehouses in order to expel pollutants generated in the houses, such ascarbon monoxide, carbon dioxide, volatile organic compounds etc. In aprior art ventilation system, outdoor air is supplied into a housethrough ductwork located in a ceiling crawl space, while indoor air isexpelled through the ductwork at the same time. The ventilation fan inthe ductwork is driven so that ventilation is performed for 24 hours. Inanother prior art ventilation system, indoor air is expelled through anexhaust fan, while outdoor air is supplied into a house through ventsinstalled in exterior walls at the same time. Also in this case,ventilation is performed for 24 hours by driving the exhaust fan.

Japanese Patent Application Publication No. 2003-79714 issued Mar. 18,2003 discloses an air cleaner equipped with an electrostatic atomizer.The atomizer is configured to produce mist of charged fine waterparticles by means of electrostatic atomization to spray the mist, andhas various advantages such as deodorization, sterilization and so on.Each of charged fine water particles constituting the mist is in theorder of nanometer in size and has a strong electric charge, andaccordingly can be widely sprayed throughout a living space and stay fora long time by force of repulsion and the size.

However, in case of the air cleaner, one or more air cleaners arerequired in addition to the ventilation system, and accordingly livingspaces are reduced.

Japanese Patent Application Publication No. 2005-233589 issued Sep. 2,2005 discloses a ventilation system equipped with an electrostaticatomizer. In this case, living spaces are not reduced by the atomizer.However, since the atomizer is located at an intermediate fan ofductwork in a ceiling crawl space, the mist produced through theatomizer can remove odors, germs, viruses, etc. in the ductwork butcannot be widely sprayed throughout a house (a living space(s)).

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a ventilation systemcapable of widely spraying mist of charged fine water particlesthroughout at least one living space in a house without reducing theliving space.

A ventilation system of the present invention (hereinafter referred toas a “first invention”) comprises: ductwork; a fan for creating acurrent of air passing through the ductwork; and an air supply outletfor supplying outdoor air into a living space of a house by means of thecurrent of air. According to a first aspect, the ventilation systemfurther comprises an electrostatic atomizer located at the side of theair supply outlet. The electrostatic atomizer is configured to producemist of charged fine water particles by means of electrostaticatomization to spray the mist into the living space. In the firstinvention, since the electrostatic atomizer is located at the side ofthe air supply outlet, the ventilation system can widely spray mist ofcharged fine water particles throughout at least one living space in ahouse without reducing the living space.

In an embodiment, the ductwork is located in a ceiling crawl space. Theair supply outlet is located at an opening of the ceiling of the livingspace and also connected with the ductwork through a passage. The fanpushes the outdoor air into the living space from the air supply outletthrough the ductwork and the passage. According to a second aspect, theventilation system of this invention (hereinafter referred to as a“second invention”) comprises a supply grille having the air supplyoutlet, the passage, the electrostatic atomizer and a controller. Thepassage comprises supply and bypass passages through which the outdoorair from the ductwork passes. The bypass passage comprises a variablepassage varying a quantity of the outdoor air passing through the bypasspassage, and a mist passage located at the downstream side of thevariable passage. The electrostatic atomizer is configured to apply highvoltage to condensation water at a position between the variable passageand the mist passage to produce mist of charged fine water particles.The controller is configured to control the variable passage to adjustthe quantity of the outdoor air passing through the bypass passage. Inthe second invention, even if the outdoor air from the ductwork isincreased or decreased, the controller controls the variable passage toadjust the quantity of the outdoor air passing through the bypasspassage and accordingly stable outdoor air can be supplied to theelectrostatic atomizer. Therefore, the mist can be constantly splayedeven if ventilation speed of the ventilation system is changed.

In an embodiment of the second invention, the supply grille furthercomprises a wind speed sensor that is configured to detect speed of theoutdoor air passing through the bypass passage to supply a sensor signalto the controller. The controller is configured to control the variablepassage based on the sensor signal. In this embodiment, the variablepassage can be suitably controlled.

In an embodiment of the first invention, the ductwork is located in aceiling crawl space. The air supply outlet is located at an opening ofthe ceiling of the living space and also connected with the ductworkthrough a passage. The fan pushes the outdoor air into the living spacefrom the air supply outlet through the ductwork and the passage. In athird aspect, the ventilation system of this invention (hereinafterreferred to as a “third invention”) comprises a supply grille having abody case; and the air supply outlet, the passage, the electrostaticatomizer and a power supply that are put in the body case. Theelectrostatic atomizer comprises: first and second electrodes and a heatexchanger that are put in the passage; and a high voltage generator. Theheat exchanger is connected with the power supply and configured to coolthe first electrode to produce condensation water on the firstelectrode. The high voltage generator is connected with the power supplyand configured to apply high voltage to the condensation water throughthe first and second electrodes to produce mist of charged fine waterparticles. In the third invention, since the heat exchanger cools thefirst electrode to produce condensation water on the first electrode,labor of water supply is unnecessary. In addition, since the air supplyoutlet, the passage, the electrostatic atomizer and the power supply areput in the body case, the supply grille having the body case can beeasily installed in the ceiling crawl space.

In an embodiment, the air supply outlet comprises an air outlet and amist outlet. The passage comprises supply and bypass passages throughwhich the outdoor air from the ductwork passes. The supply passage islocated between the ductwork and the air outlet. The bypass passage islocated between the ductwork and the mist outlet. The first and secondelectrodes and the heat exchanger is put in the bypass passage. In thisembodiment, ventilation air quantity can be secured.

In an embodiment, the air outlet side of the supply passage and the mistoutlet side of the bypass passage are I-shaped and arranged in parallel.In this embodiment, ventilation air and the mist can be effectivelydischarged downward. The supply passage and bypass passage can bearranged compactly.

In an embodiment, the supply passage is in the shape of an L. The bypasspassage is in the shape of an I, and is arranged at the inner corner ofthe supply passage to be connected between the ductwork side of thesupply passage and the mist outlet. In this embodiment, the supplypassage, bypass passage and so on can be efficiently enclosed in thebody case.

In an embodiment, the supply passage is in the shape of an L. The bypasspassage is in the shape of an I, and located opposite the inner cornerof the supply passage to be connected between the outer corner of thesupply passage and the mist outlet.

In an embodiment, the heat exchanger has a radiator that is put in thesupply passage. In this embodiment, the radiator is cooled by the airflowing through the supply passage, and accordingly can be cooledcontinuously and efficiently.

In an embodiment of the first invention, the ductwork is located in aceiling crawl space. The air supply outlet is located at an opening ofthe ceiling of the living space and also connected with the ductworkthrough a passage. The fan pushes the outdoor air into the living spacefrom the air supply outlet through the ductwork and the passage.According to a fourth aspect, the ventilation system of this invention(hereinafter referred to as a “fourth invention”) comprises: a supplygrille having the air supply outlet, the passage and the electrostaticatomizer; a room sensor that is configured to detect a state of theliving space to produce a state signal; and a controller that isconfigured to adjust a quantity of the mist based on the state signal.In the fourth invention, a quantity of the mist can be suitablycontrolled in response to a state of the living space.

In an embodiment, the room sensor is an illuminance sensor that isconfigured to detect illuminance of the living space to produce anilluminance signal. The controller is configured to change an operationmode of the electrostatic atomizer based on the illuminance signal andthereby to control a quantity of the mist. In this embodiment, a stateof the living space, for example human activity state can be judgedbased on the illuminance signal. When the illuminance level of theliving space is higher than a given illuminance level at night, it ispossible to judge that human activity state is alive. When theilluminance level of the living space is lower than the givenilluminance level at night, it is possible to judge that human activitystate is asleep. Therefore, the electrostatic atomizer can be suitablycontrolled based on the human activity state.

In an embodiment, the room sensor is a sound sensor that is configuredto detect a sound of the living space to produce a sound signal. Thecontroller is configured to change an operation mode of theelectrostatic atomizer based on the sound signal and thereby to controla quantity of the mist. In this embodiment, a state of the living space,for example human activity state can be judged based on the soundsignal. When the sound level of the living space is higher than a givensound level, it is possible to judge that human activity state is alive.When the sound level of the living space is lower than the given soundlevel, it is possible to judge that human activity state is asleep.Therefore, the electrostatic atomizer can be suitably controlled basedon the human activity state.

In an embodiment, the supply grille, the controller is configured tocontrol the electrostatic atomizer based on the state signal from theroom sensor. The supply grille, the room sensor and the controller arerelated with each other and provided for each of a plurality of livingspaces. In this embodiment, the electrostatic atomizers can be suitablycontrolled in response to each state of the plurality of living spaces.

In an embodiment, the ventilation system further comprises: a storagedevice that stores a plurality of operation modes with respect to theelectrostatic atomizer; and a selection means for selecting one of asensor operation and at least one operation that correspond to theoperation modes, respectively. The supply grille, the room sensor, thecontroller, the storage device and the selection means are related witheach other. The controller is configured: (i) to adjust a quantity ofthe mist produced by the electrostatic atomizer of the related supplygrille based on the state signal from the related room sensor inaccordance with the operation mode corresponding to the sensor operationselected through the related selection means; and also (ii) to adjust aquantity of the mist produced by the electrostatic atomizer of therelated supply grille in accordance with the operation modecorresponding to said at least one operation selected through therelated selection means. In this embodiment, a quantity of the mistproduced through the electrostatic atomizer can be suitably controlledin response to a state of the living space.

In an embodiment of the first invention, the ductwork is located in aceiling crawl space. The fan pulls off the indoor air from the livingspace through the ductwork to generate negative indoor pressure in theliving space. The air supply outlet is located at an opening of anexterior wall of the living space, and supplies outdoor air into theliving space by means of the negative indoor pressure. According to afifth aspect, the electrostatic atomizer of this invention (hereinafterreferred to as a “fifth invention”) is configured to apply high voltageto condensation water at the side of the air supply outlet to producemist of charged fine water particles. In the fifth invention, mist ofcharged fine water particles can be sprayed without reducing livingspaces. The mist can be sprayed throughout the living space by means ofthe outdoor air supplied into the living space.

In an embodiment, the ventilation system further comprises: an outletsensor for detecting whither the air supply outlet is opened or closed;and a controller. This controller is configured to operate theelectrostatic atomizer when the outlet sensor detects that the airsupply outlet is opened, and also to stop the operation of theelectrostatic atomizer when the outlet sensor detects that the airsupply outlet is closed. In this embodiment, when the air supply outletis closed, the electrostatic atomizer can be automatically stoppedwithout user's manual operation and energy can be saved.

In an embodiment, the electrostatic atomizer can be attached to anddetached from the side of the air supply outlet. In this embodiment,when mist of charged fine water particles is unnecessary, theelectrostatic atomizer can be detached from the side of the air supplyoutlet.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described in furtherdetails. Other features and advantages of the present invention willbecome better understood with regard to the following detaileddescription and accompanying drawings where:

FIG. 1 is a schematic diagram of a ventilation system, in accordancewith a first embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of an interior supply grille ofthe ventilation system;

FIG. 3 is a schematic diagram of an electrostatic atomizer of theventilation system;

FIG. 4 is a block diagram of the ventilation system;

FIG. 5 is a flow chart of the ventilation system;

FIG. 6 is a longitudinal sectional view of an interior supply grille ofa ventilation system, in accordance with a second embodiment of thepresent invention;

FIG. 7 is a side view of the interior supply grille of FIG. 6;

FIG. 8 is a cross sectional view of the interior supply grille of FIG.6;

FIGS. 9A-9D are installation explanatory diagrams of the interior supplygrille of FIG. 6;

FIG. 10 is a schematic diagram of an electrostatic atomizer of theventilation system in the second embodiment;

FIG. 11 is a perspective view of an interior supply grille in anembodiment;

FIG. 12 is a longitudinal sectional view of the interior supply grilleof FIG. 11;

FIG. 13 is a schematic diagram of a ventilation system, in accordancewith a third embodiment of the present invention;

FIG. 14 is a longitudinal sectional view of an interior supply grille ofthe ventilation system in the third embodiment;

FIG. 15 is a block diagram of the ventilation system in the thirdembodiment;

FIG. 16 is a flow chart of the ventilation system in the thirdembodiment;

FIG. 17 is a flow chart of the ventilation system in the thirdembodiment;

FIG. 18 is a flow chart of the ventilation system in the thirdembodiment;

FIG. 19 is a schematic diagram of a ventilation system, in accordancewith a fourth embodiment of the present invention;

FIGS. 20A and 20B are longitudinal sectional views of a supply grilleand an electrostatic atomizer of the ventilation system in the fourthembodiment;

FIGS. 21A and 21B are front views of the supply grille and electrostaticatomizer of the ventilation system in the fourth embodiment;

FIG. 22 is a schematic diagram of the electrostatic atomizer of theventilation system in the fourth embodiment;

FIGS. 23A and 23B are front and sectional views of the open supplygrille of the ventilation system in the fourth embodiment, 3;particularly, FIG. 23B is a sectional view along line X-X of FIG. 23A;

FIGS. 24A and 24B are front and sectional views of the close supplygrille of the ventilation system in the fourth embodiment; particularly,FIG. 24B is a sectional view along line X-X of FIG. 24A; and

FIG. 25 is a flow chart of the ventilation system in the fourthembodiment.

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

FIG. 1 shows a schematic diagram of a ventilation system 1, inaccordance with a first embodiment of the present invention. Theventilation system 1 is a residential ventilation system.

This system includes ductwork 13; a fan (ventilation fan) 141 forcreating a current of air passing through the ductwork 13; and airsupply outlets 112 for supplying outdoor air into each living space (seeliving space (room) 191 of FIG. 2) of a house by means of the current ofair.

Specifically, the ventilation system 1 includes: the ductwork 13; a heatexchanger 14 having the fan 141; an exterior supply grille 15; interiorexhaust grilles 16; an exterior exhaust grille 17; and interior supplygrilles 11 each of which has the air supply outlet 112. The exteriorsupply grille 15 and the exterior exhaust grille 17 are located outsidethe house, and the interior exhaust grilles 16 and the interior supplygrilles 11 are located at the openings of the ceilings in the house.

As shown in FIGS. 1 and 2, the ductwork 13 is located in a ceiling crawlspace 194 above ceilings 195 of the living spaces. This ductwork 13 canbe divided into: supply ductwork formed of an upstream supply duct 131,downstream supply ducts 132 and distributors 133; and exhaust ductworkformed of upstream exhaust ducts 135, a distributor(s) 136 and adownstream exhaust duct 137. The upstream supply duct 131 is connectedbetween the exterior supply grille 15 and the heat exchanger 14, and hasa filter 1311 located at the intermediate position of the duct 131. Thedownstream supply ducts 132 forms air supply lines distributed by thedistributors 133, and the air supply lines are connected between theheat exchanger 14 and each interior supply grille 11. The upstreamexhaust ducts 135 forms air exhaust lines distributed by thedistributor(s) 136, and the air exhaust lines are connected between eachinterior exhaust grilles 16 and the heat exchanger 14. The downstreamexhaust duct 137 is connected between the heat exchanger 14 and theexterior exhaust grille 17.

The heat exchanger 14 has the ventilation fan 141, and is configured toexchange heat between the supply ductwork and the exhaust ductwork.Since the ventilation system is a balanced system, the ventilation fan141 includes at least one of two fans located at both sides of thesupply ductwork and the exhaust ductwork, and creates a current of airpassing through each of the supply ductwork and the exhaust ductwork.When being activated, the ventilation fan 141 pushes outdoor air intoeach living space through the supply ductwork, and also pulls off indoorair from each living space through the exhaust ductwork. Indoor air ofeach living space is expelled outside the house. Accordingly, thecirculation of air is continuously performed. However, not limited tothis, the ventilation system 1 may have the ventilation fan 141including at least one of two fans located at both sides of the supplyductwork and the exhaust ductwork instead of the heat exchanger 14.

As shown in FIGS. 2-4, each interior supply grille 11 includes a bodycase 110 having an air supply inlet 111, the air supply outlet 112 and apassage 113 connected between the inlet 111 and the outlet 112. The airsupply inlet 111 is connected with the supply ductwork. The air supplyoutlet 112 is located at an opening of a ceiling 195 of a living space,and also connected with the supply ductwork through the passage 113. Thepassage 113 can be divided into supply and bypass passages 1131 and 1132through which outdoor air from the supply ductwork passes. The supplypassage 1131 is in the shape of an L-pipe. The bypass passage 1132 canbe subdivided into a variable passage 1133 formed of a movable partitionwall 1134 and an actuator 1135, and a mist passage 1136. However, notlimited to this, the variable passage 1133 may be other structure thatcan narrow and broaden the variable passage 1133.

Each interior supply grille 11 is also provided therein with anelectrostatic atomizer 10, an ammeter 124, a wind speed sensor 125, ahuman body sensor 126, and a controller 120.

The electrostatic atomizer 10 is configured to produce mist of chargedfine water particles by means of electrostatic atomization to spray themist into the living space. For example, the atomizer 10 is formed of ahigh voltage device 101, a heat exchanger 102 and the controller 120.

The high voltage device 101 is formed of an I-shaped electrode(electrostatic atomization pole) 1011, a ring-shaped counter electrode1012, a frame 1013 and a high voltage generator 1014. The electrode 1011is put in the frame 1013, and the counter electrode 1012 is fixed to thetop opening of the frame 1013. The high voltage generator 1014 isactivated by the controller 120 to apply high voltage between theelectrodes 1011 and 1012 through the ammeter 124.

The heat exchanger 102 is configured to cool the electrode 1011 toproduce condensation water (dew drop) on the electrode 1011. Forexample, the heat exchanger 102 is formed of a Peltier unit 1021, acooling piece 1022 and a radiator fin 1023. The Peltier unit 1021 has acooling surface and a radiation surface, and is energized through thecontroller 120 and then cools the cooling surface and also radiates heatfrom the radiation surface. The cooling surface is in contact with onesurface of the cooling piece 1022, and this cooling piece 1022 functionsas a cooling part of the heat exchanger 102. The cooling piece 1022 isalso fit into the bottom opening of the frame 1013, and the base of theelectrode 1011 is fixed on the other surface of cooling piece 1022. Theradiation surface is in contact with the base of the radiator fin 1023,and this radiator fin 1023 functions as a radiator of the heat exchanger102.

As shown in FIG. 2, the electrostatic atomizer 10 is fixed inside thebody case 110 so that the radiator fin 1023 is put in the supply passage1131. Accordingly, the radiator fin 1023 can radiate heat efficiently bymeans of outdoor air passing through the supply passage 1131. The highvoltage device 101 is also put between the variable passage 1133 and themist passage 1136 so that the bypass passage 1132 is constituted by thevariable passage 1133, a through hole 1013 a of the frame 1013, anopening 1012 a of the counter electrode 1012, and the mist passage 1136.

The downstream end of the partition wall 1134 in the variable passage1133 is hinged on the side of the heat exchanger 102 of theelectrostatic atomizer 10, and the wall 1134 can be pivoted through theactuator 1135. This actuator 1135 has an extendable axis of which tip isfixed to the partition wall 1134, and is driven under the control of thecontroller 120 to adjust a pivot angle of the partition wall 1134. Themist passage 1136 is provided therein with the wind speed sensor 125that is configured to detect speed of outdoor air passing through thebypass passage 1132 to supply a sensor signal to the controller 120.However, not limited to this, the wind speed sensor 125 may be put inthe variable passage 1133.

The air supply outlet 112 includes an outlet (air outlet) 1121 of thesupply passage 1131 and an outlet (mist outlet) 1122 of the bypasspassage 1132, and these outlets 1121 and 1122 are located at an openingof a ceiling 195 of a living space. The human body sensor 126 isarranged between the outlets 1121 and 1122, and is configured to detectwhether or not a human is in the living space and then to supply a humanbody sensor signal to the controller 120. However, not limited to this,the ventilation system 1 may have another sensor such as an odor sensorfor detecting an odor to supply an odor sensor signal to the controller120, or the like in addition to or instead of the human body sensor 126.

The controller 120 comprises a microcomputer, and is configured tocontrol the electrostatic atomizer 10 and the actuator 1135 based oneach signal from the ammeter 124, the wind speed sensor 125 and thehuman body sensor 126.

That is, when receiving the human body sensor signal indicating that ahuman(s) is in the living space, the controller 120 energizes the heatexchanger 102 to cool the electrode 1011 usually supplied with outdoorair through the variable passage 1133. The high voltage device 101 isalso activated. Accordingly, air around the electrode 1011 is cooled andthen condensation water is produced on the electrode 1011. Since highvoltage is applied between the electrode 1011 and the counter electrode1012, the condensation water is electrostatically atomized and then mistof charged fine water particles is produced. The mist is carried by ionwind and the outdoor air passing through the bypass passage 1132 andthen mightily sprayed throughout the living space from the mist outlet1122. In this case, the controller 120 controls a quantity of the mistby changing a discharge current obtained from the ammeter 124 or an onand off duty ratio of intermittent operation. In an example, the highvoltage device 101 may generate the high voltage after the condensationwater (dew drop) is produced (see Japanese Patent ApplicationPublication No. 2006-239632 issued Sep. 14, 2006 and Japanese PatentApplication Publication No. 2006-122819 issued May 18, 2006, which areincorporated herein by reference, especially paragraph 0022 in theformer).

The controller 120 also controls the actuator 1135 based on a wind speedsensor signal from the wind speed sensor 125 as shown in FIG. 5. Thatis, the controller 120 detects wind speed of the outdoor air flowingthrough the bypass passage 1132 based on the wind speed sensor signal,and then judges whether or not the wind speed is in a reference range.The reference range is set to a range by which the heat exchanger 102can produce a proper quantity of mist of charged fine water particlesand the mist can be mightily sprayed into the living space from the mistoutlet 1122. In case that the wind speed is below the reference range,the controller 120 controls to shorten the extendable axis of theactuator 1135 to pivot the partition wall 1134 so that the variablepassage 1133 is broadened. In case that the wind speed is above thereference range, the controller 120 controls to lengthen the extendableaxis of the actuator 1135 to pivot the partition wall 1134 so that thevariable passage 1133 is narrowed. In case that the wind speed is in thereference range, the controller 120 controls to fix the actuator 1135 tokeep the size of the variable passage 1133.

In the first embodiment, even if the outdoor air from the ductwork 13(i.e., supply ductwork) is increased or decreased, each wind speed ofthe bypass passages 1131 of the interior supply grilles 11 is kept inthe reference range.

In an embodiment, the controller 120 (e.g., a storage device) has aplurality of reference ranges corresponding to the reference range ofthe first embodiment. The controller 120 also uses a reference rangeselected from the reference ranges by a selection means such a controlpanel put in a living space or the like.

Second Embodiment

FIGS. 6-8 and 9A-9D show schematic diagrams of an interior supply grille21 of a ventilation system, in accordance with a second embodiment ofthe present invention. This ventilation system is formed in the same wayas the first embodiment except the interior supply grille 21.

The interior supply grille 21 includes a body case 210 having an airsupply inlet 211, the air supply outlet 212 and a passage 213 connectedbetween the inlet 211 and the outlet 212. The air supply inlet 211 isconnected with the supply ductwork of the ventilation system. The airsupply outlet 212 is located at an opening 296 of a ceiling 295 of aliving space 291, and also connected with the supply ductwork throughthe passage 213. The passage 213 can be divided into supply and bypasspassages 2131 and 2132 through which outdoor air from the supplyductwork passes. The supply passage 2131 is formed of an L-shaped supplypipe, and the base end of this supply pipe sticks out from the side ofthe body case 210.

As shown in FIG. 10, the interior supply grille 21 is also providedtherein with an electrostatic atomizer 20, an ammeter 224, a powersupply 223, a human body sensor (not shown) and a controller 220. Thepower supply 223 has a connector 2231 that is connected with the outputof the supply 223 via lead wires from inside of the body case 210. Thispower supply 223 is connected with a connector 2232 of a commercialpower source via the connector 2231 to supply electric power to theelectrostatic atomizer 20, the controller 220 and so on.

The electrostatic atomizer 20 is configured to produce mist of chargedfine water particles by means of electrostatic atomization to spray themist into the living space. The atomizer 20 includes a high voltagedevice 201 and a heat exchanger 202.

The high voltage device 201 is formed of an I-shaped electrode (a firstelectrode) 2011, a ring-shaped counter electrode (a second electrode)2012, a frame 2013 and a high voltage generator 2014. The electrode 2011is put in the frame 2013, and the counter electrode 2012 is fixed to thetop opening of the frame 2013. The high voltage generator 2014 isactivated by the controller 220 and then uses electric power suppliedfrom the power supply 223 to apply high voltage between the electrodes2011 and 2012 through the ammeter 224.

The heat exchanger 202 is configured to cool the electrode 2011 toproduce condensation water on the electrode 2011. For example, the heatexchanger 202 is formed of a Peltier unit 2021, a cooling piece 2022 anda radiator fin 2023. The Peltier unit 2021 has a cooling surface and aradiation surface, and is energized from the power supply 223 throughthe controller 220 and then cools the cooling surface and also radiatesheat from the radiation surface. The cooling surface is in contact withone surface of the cooling piece 2022, and this cooling piece 2022functions as a cooling part of the heat exchanger 202. The cooling piece2022 is also fit into the bottom opening of the frame 2013, and the baseof the electrode 2011 is fixed on the other surface of cooling piece2022. The radiation surface is in contact with the base of the radiatorfin 2023, and this radiator fin 2023 functions as a radiator of the heatexchanger 202.

As shown in FIGS. 6 and 10, the electrode 2011, the counter electrode2012, the frame 2013 and the heat exchanger 202 are unified to be fixedinside the body case 210. The radiator fin 2023 is put in the supplypassage 2131, while the electrode 2011, the counter electrode 2012 andthe frame 2013 is put in the I-shaped bypass passage 2132. The outdoorair from the supply ductwork can pass through the bypass passage 2132via at least one through hole of the frame 2013 and an opening 2012 a ofthe counter electrode 2012. The bypass passage 2132 is provided thereinwith a cylinder-shaped silencer 2137 for reducing the amount of noisewhen the mist is produced. The voltage generator 2014, the power supply223 and the controller 220 are put in storage spaces 2103 in the bodycase 210.

The air supply outlet 212 includes an outlet (air outlet) 2121 of thesupply passage 2131 and an outlet (mist outlet) 2122 of the bypasspassage 2132, and these outlets 2121 and 2122 are located at an openingof the ceiling 295 of the living space 291. The human body sensor (notshown) is arranged between the outlets 2121 and 2122, and is configuredto detect whether or not a human is in the living space and then tosupply a human body sensor signal to the controller 220.

The supply passage 2131 is in the shape of an L. The bypass passage 2132is in the shape of an I, and is arranged at the inner corner of thesupply passage 2131. The bypass passage 2132 is also arranged inparallel with the air outlet (2121) side of the supply passage 2131, andis connected between the ductwork side of the passage 2131 and the mistoutlet 2122. Accordingly, the supply passage 2131 and bypass passage2132 can be arranged compactly in the body case 210.

As shown in FIG. 9A, the body case 210 has an inclined recess 2101 atthe opposite side of the air supply inlet 211. The body case 210 alsohas a flange 2102 at the air supply outlet (212) side. Accordingly,after the air supply inlet 211 and the connector 2231 are connected witha downstream supply duct 232 of the supply ductwork and the connector2232, respectively, the interior supply grille 21 can be inserted intothe opening 296 as shown in FIGS. 9B-9D. Specifically, as shown in FIG.9A, the downstream supply duct 232 having the connector 2232 is pulledinto the living space 291 through the opening 296. The air supply inlet211 and the connector 2231 are then connected with the downstream supplyduct 232 and the connector 2232, respectively. As shown in FIG. 9B, theinterior supply grille 21 is laid and then the air supply inlet (211)side of the grille 21 is inserted into the opening 296. As shown inFIGS. 9C and 9D, the interior supply grille 21 is inserted into theopening 296 while rotating the grille 21 until the flange 2102 comesinto contact with the ceiling 295. Subsequently, the flange 2102 isfixed on the ceiling 295 by means of, for example, screw fixation.

In the same way as the first embodiment, the controller 220 comprises amicrocomputer, and is configured to control the electrostatic atomizer20 (i.e., high voltage generator 2014 and the Peltier unit 2021) basedon each signal from the ammeter 224 and the human body sensor.

When receiving the human body sensor signal indicating that a human isin the living space 291, the controller 220 energizes the heat exchanger202 through the power supply 223 to cool the electrode 2011 usuallysupplied with outdoor air. Accordingly, air around the electrode 2011 iscooled and then condensation water is produced on the electrode 2011.Since high voltage is applied between the electrode 2011 and the counterelectrode 2012, the condensation water is electrostatically atomized andthen mist of charged fine water particles is produced. The mist iscarried by ion wind and the outdoor air passing through the bypasspassage 2132 and then widely sprayed throughout the living space 291from the mist outlet 2122.

In the second embodiment, the heat exchanger 202 cools the electrode2011 to produce condensation water on the electrode 2011, andaccordingly labor of water supply for each interior supply grille 21 ina ceiling crawl space 294 is unnecessary. Since outdoor air is usuallysupplied for the electrode 2011, condensation water can be producedcontinuously and efficiently.

The interior supply grille 21 has the electrostatic atomizer 20, theammeter 224, the power supply 223, the human body sensor and thecontroller 220, and therefore can be easily installed by connecting theconnectors 2231 and 2232.

Since the bypass passage 1132 and the mist outlet 2122 are provided inaddition to the supply passage 2131 and the air outlet 2121, ventilationair quantity can be secured independent of the structure for producingthe mist.

The bypass passage 2132 is arranged at the inner corner of the supplypassage 2131 in parallel with the air outlet side of the supply passage2131, and accordingly, the supply passage 2131 and bypass passage 2132can be arranged compactly in the body case 210. Because of this, aninterior supply grille 21 can be installed instead of a conventionalinterior supply grille.

The electrostatic atomizer 20 is automatically activated in response tothe human body sensor signal indicating that a human is in the livingspace 291, and thereby capable of saving energy. For example, after aperson to whom pollen sticks enters the living space, the systemautomatically sprays the mist and accordingly is effective inpollinosis. Because the mist of charged fine water particles has thefunction of inactivating allergen substances such as pollen, in additionto elimination (of microbes) and deodorization functions.

In an embodiment, the ventilation system has a means that has a coolingpart like the heat exchanger 202 and produces and stores condensationwater. The electrode 2011 is made of porous material, and the storedwater is supplied to the electrode 2011 by means of capillary phenomenonof the electrode 2011 itself.

In an embodiment, as shown in FIGS. 11 and 12, the bypass passage 2132is located opposite the inner corner of the supply passage 2131, and isalso arranged in parallel with the air outlet (2121) side of the supplypassage 2131. The bypass passage 2132 is also connected between theouter corner of the supply passage 2131 and the mist outlet 2122. Alsoin this case, the outdoor air from the supply ductwork passes throughthe mist outlet 2122 from the radiator fin (2023) side, and accordinglythe radiator fin 2023 can be cooled continuously and efficiently.

Third Embodiment

FIG. 13 shows a schematic diagram of a ventilation system 3, inaccordance with a third embodiment of the present invention. In the sameway as the first embodiment, the ventilation system 3 includes ductwork33, a heat exchanger 34 having a fan (ventilation fan), an exteriorsupply grille 35, interior exhaust grilles 36 and an exterior exhaustgrille 37. The ductwork 33 has: supply ductwork formed of an upstreamsupply duct 331 (having a filter 3311), downstream supply ducts 332 anddistributors 333; and exhaust ductwork formed of an upstream exhaustduct(s) 335, and a downstream exhaust duct 337. In case that a pluralityof upstream exhaust ducts 335 are used, a distributor(s) for the ducts335 is further added.

As shown in FIGS. 13 and 14, the ventilation system 3 is characterizedby interior supply grilles 31 each of which has an air supply outlet312. At least one interior supply grille 31 is installed on a ceiling395 of each living space 391 having its own partition walls. On theother hand, the interior exhaust grilles 36 are installed on a ceilingof a passageway 393 to each living space 391.

As shown in FIGS. 13-15, each interior supply grille 31 includes a bodycase 310 having an air supply inlet 311, the air supply outlet 312, anda passage 313 connected between the inlet 311 and the outlet 312, inalmost the same way as the first embodiment. The passage 313 includessupply and bypass passages 3131 and 3132 through which outdoor air fromthe supply ductwork passes, but the bypass passage 3132 is differentfrom the bypass passage 1132 in that the passage 3132 includes aconstant passage 3133 and a mist passage 3136.

Each interior supply grille 31 is also provided therein with anelectrostatic atomizer 30, a storage device 322, an ammeter 324, and acontroller 320. In the same way as the first embodiment, theelectrostatic atomizer 30 is formed of a high voltage device 301, a heatexchanger 302 and the controller 320. The high voltage device 301 isformed of an I-shaped electrode 3011, a ring-shaped counter electrode3012, a frame 3013 and a high voltage generator 3014. The heat exchanger302 is formed of a Peltier unit 3021, a cooling piece 3022 and aradiator fin 1023. The storage device 322 stores a plurality ofoperation modes (operation programs) for the electrostatic atomizer 30,and so on.

Each interior supply grille 31 is further provided with a control panel(selection means) 321 and a room sensor 326 that are installed in thecorresponding living space 391. The control panel 321 is configured tosupply the controller 320 with a control signal indicating an operationselected by a user from a plurality of operations respectivelycorresponding to said operation modes, or the like. The room sensor 326is configured to detect a state of the living space to produce a statesignal. That is, the illuminance sensor 3261 detects illuminance of theliving space to produce an illuminance signal corresponding to theilluminance, and then supplied the signal to the controller 320. Thesound sensor 3262 detects sound of the living space to produce a soundsignal corresponding to the sound (level), and then supplied the signalto the controller 320. However, not limited to this, the room sensor 326may be the other sensor such as a human body sensor, an odor sensor orthe like.

The room sensor 326, the control panel 321 and at least one interiorsupply grille 31 are related with each other and provided for each ofthe living spaces of the house.

The controller 320 comprises a microcomputer, and is configured tocontrol the related electrostatic atomizer 30 based on a necessarysignal from each of the related ammeter 324 and room sensor 326 inaccordance with the operation mode selected from the related storagedevice 322 through the related control panel 321.

First, the fundamental operation of the controller 320 is explained.When the electrostatic atomizer 30 is activated, the controller 320energizes the heat exchanger 302 to cool the electrode 3011 usuallysupplied with outdoor air through the bypass passage 3132. Accordingly,air around the electrode 3011 is cooled and then condensation water isproduced on the electrode 3011. Since high voltage is applied betweenthe electrode 3011 and the counter electrode 3012, the condensationwater is electrostatically atomized and then mist of charged fine waterparticles is produced. The mist is carried by ion wind and the outdoorair passing through the bypass passage 3132 and then sprayed throughoutthe living space 391 from the mist outlet 3122. Accordingly, it ispossible to widely spray the mist of charged fine water particlesthroughout each living space 391 in a house without reducing each livingspace 391.

The illuminance sensor operation of the controller 320 is explained withreference to FIG. 16. In a living space 391, when receiving a controlsignal indicating a daytime operation selected by a user, the controller320 controls the electrostatic atomizer 30 in accordance with the normaloperation mode that is stored in the storage device 322 and correspondsto the daytime operation. For example, the controller 320 repeatedlycontrols the electrostatic atomizer 30 in accordance with anintermittent operation of turning the atomizer 30 on and off for 10 and30 minutes, respectively.

When receiving a control signal indicating a nighttime operationselected by a user, the controller 320 changes its operation mode inresponse to the illuminance signal. That is, when the illuminanceobtained from the illuminance signal is equal to or higher thanreference illuminance, the controller 320 controls the electrostaticatomizer 30 in accordance with the normal operation mode.

When the illuminance is lower than the reference illuminance, thecontroller 320 controls the electrostatic atomizer 30 in accordance withthe low operation mode that is stored in the storage device 322 andcorresponds to the nighttime operation. For example, the controller 320repeatedly controls the electrostatic atomizer 30 in accordance with anintermittent operation of which on and off duty ratio is changed so thata quantity of the mist is less than that of the normal operation mode.Specifically, this low operation mode (intermittent operation) is set toturn the atomizer 30 on and off for, e.g., 10 and 60 minutes,respectively. In this case, a quantity of the mist is reduced to abouthalf of that of the normal operation mode. However, not limited to this,a quantity of the mist may be reduced by changing a discharge currentobtained from the ammeter 324, or changing the discharge current and theon and off duty ratio of the intermittent operation.

The priority assigned operation of the controller 320 is explained withreference to FIG. 17. In a living space 391, when receiving a controlsignal indicating that priority is assigned to the illuminance sensor3261 by a user and then receiving a control signal indicating a daytimeoperation selected by the user, the controller 320 controls theelectrostatic atomizer 30 in accordance with the normal operation mode.

When receiving a control signal indicating that priority is assigned tothe illuminance sensor 3261 by the user and then receiving a controlsignal indicating a nighttime operation selected by the user, thecontroller 320 changes its operation mode in response to the illuminancesignal. When the illuminance obtained from the illuminance signal isequal to or higher than the reference illuminance, the controller 320controls the electrostatic atomizer 30 in accordance with the normaloperation mode. When the illuminance is lower than the referenceilluminance, the controller 320 controls the electrostatic atomizer 30in accordance with the low operation mode.

When receiving a control signal indicating that priority is assigned tothe sound sensor 3262 by the user, the controller 320 changes itsoperation mode in response to the sound signal. That is, when the soundobtained from the sound signal is equal to or larger than referencesound, the controller 320 controls the electrostatic atomizer 30 inaccordance with the normal operation mode. When the sound is lower thanthe reference sound, the controller 320 controls the electrostaticatomizer 30 in accordance with the low operation mode.

The other operation of the controller 320 is explained with reference toFIG. 18. In a living space 391, if a user selects a sensor operationthrough the control panel 321, said priority assigned operation (seeFIG. 17) is performed.

When receiving a control signal indicating a standard operation selectedby the user, the controller 320 controls the electrostatic atomizer 30in accordance with the standard operation mode that is stored in thestorage device 322 and corresponds to the standard operation. Thisstandard operation mode is previously stored in the storage device 322.However, not limited to this, the storage device 322 may store aplurality of standard operation modes. In this case, one of the standardoperation modes is easily selected by a user through the control panel321.

When receiving a control signal indicating an option operation selectedby the user, the controller 320 controls the electrostatic atomizer 30in accordance with the option operation mode that is stored in thestorage device 322 and corresponds to the option operation. This optionoperation mode is the operation mode that was performed on a particulardate such as the previous day or the like and stored in the storagedevice 322 by the user. However, not limited to this, the storage device322 may store a plurality of option operation modes. The optionoperation modes are set based operation modes performed on the differentdates. In this case, one of the option operation modes is easilyselected by a user through the control panel 321.

In the third embodiment, the ventilation system 3 can appropriatelyspray the mist of charged fine water particles into each of the livingspaces in response to each state (state change) of the living spaces.

Fourth Embodiment

FIG. 19 shows a schematic diagram of a ventilation system 4, inaccordance with a fourth embodiment of the present invention. Theventilation system 4 includes: the ductwork 43; a fan (exhaust fan) 441;interior exhaust grilles 46; an exterior exhaust grille 47; and supplygrilles 41 each of which has an air supply outlet 412. The interiorexhaust grilles 46 are located at the openings of the ceilings of apassageway 493 in a house, and the exterior exhaust grille 47 is locatedoutside the house. However, not limited to the passageway, the exteriorexhaust grille 47 can be located outside toilet, bathroom, kitchen orthe like.

The ductwork 43 is located in a ceiling crawl space above the ceiling ofthe passageway 493. This ductwork 43 is provided with exhaust ductwork,and also connected with the supply grilles 41 via the interior exhaustgrilles 46 and upstream exhaust lines 435 passing through gaps of doors4931 in the passageway 493. The exhaust ductwork is formed of adownstream exhaust duct 437 connected between the interior exhaustgrilles 46 and the exterior exhaust grille 47. The exhaust fan 441 pullsoff indoor air from living spaces 491 through the interior exhaustgrilles 46 and the exhaust ductwork, and then generates negative indoorpressure in each of the living spaces 491.

As shown in FIGS. 19, 20A and 20B, each of the supply grilles 41 islocated at an opening 496 of an exterior wall 492 of a living space 491in the house, and supplies outdoor air into the living space 491 bymeans of the negative indoor pressure. For example, as shown in FIGS.20A, 20B, 21A, 21B, 22, 23A, 23B, 24A and 24B, the supply grille 41 isformed of a filter 410, a vent fixture 411 as the air supply outlet 412,and a shutter 413. The filter 410 covers the opening 496 to removepollutants such as pollen, fine particles and so on form the outdoorair. The vent fixture 411 has ventilation holes 4111 arranged radially,and is installed inside the filter 410. The shutter 413 has holes 4131and covers 4132 for opening and closing over the outside of theventilation holes 4111, and is located between the filter 410 and thevent fixture 411. The shutter 413 also has a knob 4130 for rotating theshutter 413 around the knob 4130 in a given rotation range. In FIGS. 23Aand 23B, the ventilation holes 4111 are opened. In FIGS. 24A and 24B,the ventilation holes 4111 are closed.

A recess 4921 having a wall socket 4922 is formed inside the upper partof each opening 496, and an electrostatic atomizer 40 is fit into eachrecess 4921. The electrostatic atomizer 40 can be attached to anddetached from the recess 4921, and is configured to apply high voltageto condensation water at the side of the air supply outlet 412 toproduce mist of charged fine water particles.

For example, the electrostatic atomizer 40 has a case 400, and also hasa high voltage device 401, a heat exchanger 402, a power plug 4231, anammeter 424, a shutter sensor 427, a fan 428 and the controller 420 thatare put in the case 400. The case 400 has an air inlet 4001 and a mistoutlet 4002 at the upper front and the bottom of the case, respectively.

In the same way as the first embodiment, the high voltage device 401 isformed of an I-shaped electrode 4011, a ring-shaped counter electrode4012, a frame 4013 and a high voltage generator 4014. Similarly, theheat exchanger 402 is formed of a Peltier unit 4021, a cooling piece4022 and a radiator fin 4023. The radiator fin 4023 is cooled by the fan428. However, not limited to the heat exchanger 402, the electrostaticatomizer 40 may have a means for producing condensation water on thecooling piece 4022. In this case, the electrode 4011 with a suction bodymay carry the condensation water to the top by means of capillaryphenomenon of the suction body.

The power plug 4231 is located at the rear of the case 400, and justconnected to the wall socket 4922 when the electrostatic atomizer 40 isfit into the recess 4921. The shutter sensor 427 is configured to detectwhether the ventilation holes 4111 are opened or closed, and is locatedat the edge side of the shutter 413. For example, the shutter sensor 427is a proximity sensor, and supplies a shutter sensor signal to thecontroller 420. The shutter sensor 427 is turned on when the ventilationholes 4111 are opened, namely when the cover 4132 is in the proximity ofthe shutter sensor 427 (FIGS. 23A and 23B). The shutter sensor 427 isturned off when the ventilation holes 4111 are closed (FIGS. 24A and24B).

The electrostatic atomizer 40 is fixed in the recess 4921 so that theair inlet 4001, the fan 428, the radiator fin 4023, the Peltier unit4021, the cooling piece 4022, the electrode 4011, the counter electrode4012 and the mist outlet 4002 are arranged in this order from upward todownward. Accordingly, an air passage is formed from the air inlet 4001to the mist outlet 4002, and the counter electrode 4012 is located tothe air supply outlet (vent fixture) side. Specifically, the counterelectrode 4012 is located above the inside of the air supply outlet 412(vent fixture 411). However, not limited to above the inside of the airsupply outlet 412, the counter electrode 4012 may be located so that themist is sprayed inside the air supply outlet 412 (vent fixture 411).

The controller 420 comprises a microcomputer, and is configured tocontrol the high voltage generator 4014, the Peltier unit 4021 and thefan 428 based on each signal from the ammeter 424 and the shutter sensor427. For example, when receiving the shutter sensor signal indicatingthat the shutter sensor 427 is turned on, the controller 420 activatesthe high voltage generator 4014, the Peltier unit 4021 and the fan 428as shown in FIG. 25. Thereby, the fan 428 operates, and theelectrostatic atomizer 40 produces mist of charged fine water particles.That is, the controller 420 energizes the heat exchanger 402 to cool theelectrode 4011 usually supplied with indoor air from the air inlet 4001.Accordingly, air around the electrode 4011 is cooled and thencondensation water is produced on the electrode 4011. Since high voltageis applied between the electrode 4011 and the counter electrode 4012,the condensation water is electrostatically atomized and then mist ofcharged fine water particles is produced. The mist is carried by ionwind, the indoor air from the air inlet 4001 and the outdoor air fromthe supply grille 41, and then sprayed throughout the living space. Whenreceiving the shutter sensor signal indicating that the shutter sensor427 is turned off, the controller 420 stops the high voltage generator4014, the Peltier unit 4021 and the fan 428.

In the fourth embodiment, it is possible to widely spray mist of chargedfine water particles throughout each living space 491 in the housewithout reducing each living space 491. Moreover, the mist can be widelysprayed by means of a current of outdoor air passing through a supplygrille 41.

Although the present invention has been described with reference tocertain preferred embodiments, numerous modifications and variations canbe made by those skilled in the art without departing from the truespirit and scope of this invention.

1. A ventilation system, comprising: ductwork; a fan for creating acurrent of air passing through the ductwork; and an air supply outletfor supplying outdoor air into a living space of a house by means of thecurrent of air; wherein the ventilation system further comprises anelectrostatic atomizer located at the side of the air supply outlet, theelectrostatic atomizer being configured to produce mist of charged finewater particles by means of electrostatic atomization to spray the mistinto the living space.
 2. The ventilation system of claim 1, wherein:the ductwork is located in a ceiling crawl space; the air supply outletis located at an opening of the ceiling of the living space and alsoconnected with the ductwork through a passage; and the fan pushes theoutdoor air into the living space from the air supply outlet through theductwork and the passage; wherein the ventilation system comprises asupply grille having the air supply outlet, the passage, theelectrostatic atomizer and a controller, the passage comprising supplyand bypass passages through which the outdoor air from the ductworkpasses, the bypass passage comprising a variable passage varying aquantity of the outdoor air passing through the bypass passage, and amist passage located at the downstream side of the variable passage, theelectrostatic atomizer being configured to apply high voltage tocondensation water at a position between the variable passage and themist passage to produce mist of charged fine water particles, thecontroller being configured to control the variable passage to adjustthe quantity of the outdoor air passing through the bypass passage. 3.The ventilation system of claim 2, wherein: the supply grille furthercomprises a wind speed sensor that is configured to detect speed of theoutdoor air passing through the bypass passage to supply a sensor signalto the controller; and the controller is configured to control thevariable passage based on the sensor signal.
 4. The ventilation systemof claim 1, wherein: the ductwork is located in a ceiling crawl space;the air supply outlet is located at an opening of the ceiling of theliving space and also connected with the ductwork through a passage; andthe fan pushes the outdoor air into the living space from the air supplyoutlet through the ductwork and the passage; wherein the ventilationsystem comprises a supply grille having: a body case; and the air supplyoutlet, the passage, the electrostatic atomizer and a power supply thatare put in the body case; the electrostatic atomizer comprising: firstand second electrodes and a heat exchanger that are put in the passage;and a high voltage generator; the heat exchanger being connected withthe power supply and configured to cool the first electrode to producecondensation water on the first electrode, the high voltage generatorbeing connected with the power supply and configured to apply highvoltage to the condensation water through the first and secondelectrodes to produce mist of charged fine water particles.
 5. Theventilation system of claim 4, wherein: the air supply outlet comprisingan air outlet and a mist outlet; and the passage comprising supply andbypass passages through which the outdoor air from the ductwork passes,the supply passage being located between the ductwork and the airoutlet, the bypass passage being located between the ductwork and themist outlet, the first and second electrodes and the heat exchangerbeing put in the bypass passage.
 6. The ventilation system of claim 5,wherein the air outlet side of the supply passage and the mist outletside of the bypass passage are I-shaped and arranged in parallel.
 7. Theventilation system of claim 6, wherein: the supply passage is in theshape of an L; and the bypass passage is in the shape of an I, and isarranged at the inner corner of the supply passage to be connectedbetween the ductwork side of the supply passage and the mist outlet. 8.The ventilation system of claim 6, wherein: the supply passage is in theshape of an L; and the bypass passage is in the shape of an I, andlocated opposite the inner corner of the supply passage to be connectedbetween the outer corner of the supply passage and the mist outlet. 9.The ventilation system of claim 5, wherein the heat exchanger has aradiator that is put in the supply passage.
 10. The ventilation systemof claim 1, wherein: the ductwork is located in a ceiling crawl space;the air supply outlet is located at an opening of the ceiling of theliving space and also connected with the ductwork through a passage; andthe fan pushes the outdoor air into the living space from the air supplyoutlet through the ductwork and the passage; wherein the ventilationsystem comprises: a supply grille having the air supply outlet, thepassage and the electrostatic atomizer; a room sensor that is configuredto detect a state of the living space to produce a state signal; and acontroller that is configured to adjust a quantity of the mist based onthe state signal.
 11. The ventilation system of claim 10, wherein: theroom sensor is an illuminance sensor that is configured to detectilluminance of the living space to produce an illuminance signal; andthe controller is configured to change an operation mode of theelectrostatic atomizer based on the illuminance signal and thereby tocontrol a quantity of the mist.
 12. The ventilation system of claim 10,wherein: the room sensor is a sound sensor that is configured to detecta sound of the living space to produce a sound signal; and thecontroller is configured to change an operation mode of theelectrostatic atomizer based on the sound signal and thereby to controla quantity of the mist.
 13. The ventilation system of claim 10, wherein:the controller is configured to control the electrostatic atomizer basedon the state signal from the room sensor; and the supply grille, theroom sensor and the controller are related with each other and providedfor each of a plurality of living spaces.
 14. The ventilation system ofclaim 10, further comprising: a storage device that stores a pluralityof operation modes with respect to the electrostatic atomizer; and aselection means for selecting one of a sensor operation and at least oneoperation that correspond to the operation modes, respectively; wherein:the supply grille, the room sensor, the controller, the storage deviceand the selection means are related with each other; and the controlleris configured: (i) to adjust a quantity of the mist produced by theelectrostatic atomizer of the related supply grille based on the statesignal from the related room sensor in accordance with the operationmode corresponding to the sensor operation selected through the relatedselection means; and also (ii) to adjust a quantity of the mist producedby the electrostatic atomizer of the related supply grille in accordancewith the operation mode corresponding to said at least one operationselected through the related selection means.
 15. The ventilation systemof claim 1, the ductwork is located in a ceiling crawl space; the fanpulls off the indoor air from the living space through the ductwork togenerate negative indoor pressure in the living space; and the airsupply outlet is located at an opening of an exterior wall of the livingspace, and supplies outdoor air into the living space by means of thenegative indoor pressure; wherein the electrostatic atomizer isconfigured to apply high voltage to condensation water at the side ofthe air supply outlet to produce mist of charged fine water particles.16. The ventilation system of claim 15, further comprising: an outletsensor for detecting whether the air supply outlet is opened or closed;and a controller that is configured to operate the electrostaticatomizer when the outlet sensor detects that the air supply outlet isopened, and also to stop the operation of the electrostatic atomizerwhen the outlet sensor detects that the air supply outlet is closed. 17.The ventilation system of claim 15, wherein the electrostatic atomizercan be attached to and detached from the side of the air supply outlet.18. The ventilation system of claim 11, wherein: the controller isconfigured to control the electrostatic atomizer based on the statesignal from the room sensor; and the supply grille, the room sensor andthe controller are related with each other and provided for each of aplurality of living spaces.
 19. The ventilation system of claim 11,further comprising: a storage device that stores a plurality ofoperation modes with respect to the electrostatic atomizer; and aselection means for selecting one of a sensor operation and at least oneoperation that correspond to the operation modes, respectively; wherein:the supply grille, the room sensor, the controller, the storage deviceand the selection means are related with each other; and the controlleris configured: (i) to adjust a quantity of the mist produced by theelectrostatic atomizer of the related supply grille based on the statesignal from the related room sensor in accordance with the operationmode corresponding to the sensor operation selected through the relatedselection means; and also (ii) to adjust a quantity of the mist producedby the electrostatic atomizer of the related supply grille in accordancewith the operation mode corresponding to said at least one operationselected through the related selection means.
 20. The ventilation systemof claim 16, wherein the electrostatic atomizer can be attached to anddetached from the side of the air supply outlet.